2 * Copyright (c) 2000 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/sys/kern/subr_taskqueue.c,v 1.1.2.3 2003/09/10 00:40:39 ken Exp $
27 * $DragonFly: src/sys/kern/subr_taskqueue.c,v 1.13 2008/06/07 11:44:04 mneumann Exp $
30 #include <sys/param.h>
31 #include <sys/queue.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/taskqueue.h>
35 #include <sys/interrupt.h>
37 #include <sys/malloc.h>
38 #include <sys/kthread.h>
39 #include <sys/thread2.h>
40 #include <sys/spinlock.h>
41 #include <sys/spinlock2.h>
42 #include <sys/serialize.h>
44 #include <machine/varargs.h>
46 MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues");
48 static STAILQ_HEAD(taskqueue_list, taskqueue) taskqueue_queues;
49 static struct lock taskqueue_queues_lock;
52 STAILQ_ENTRY(taskqueue) tq_link;
53 STAILQ_HEAD(, task) tq_queue;
55 taskqueue_enqueue_fn tq_enqueue;
58 struct task *tq_running;
59 struct spinlock tq_lock;
60 struct thread **tq_threads;
65 #define TQ_FLAGS_ACTIVE (1 << 0)
66 #define TQ_FLAGS_BLOCKED (1 << 1)
67 #define TQ_FLAGS_PENDING (1 << 2)
69 static void taskqueue_run(struct taskqueue *queue, int lock_held);
72 TQ_LOCK_INIT(struct taskqueue *tq)
74 spin_init(&tq->tq_lock);
78 TQ_LOCK_UNINIT(struct taskqueue *tq)
80 spin_uninit(&tq->tq_lock);
84 TQ_LOCK(struct taskqueue *tq)
86 spin_lock(&tq->tq_lock);
90 TQ_UNLOCK(struct taskqueue *tq)
92 spin_unlock(&tq->tq_lock);
96 TQ_SLEEP(struct taskqueue *tq, void *ident, const char *wmesg)
98 ssleep(ident, &tq->tq_lock, 0, wmesg, 0);
102 taskqueue_create(const char *name, int mflags,
103 taskqueue_enqueue_fn enqueue, void *context)
105 struct taskqueue *queue;
107 queue = kmalloc(sizeof(*queue), M_TASKQUEUE, mflags | M_ZERO);
110 STAILQ_INIT(&queue->tq_queue);
111 queue->tq_name = name;
112 queue->tq_enqueue = enqueue;
113 queue->tq_context = context;
114 queue->tq_flags |= TQ_FLAGS_ACTIVE;
117 lockmgr(&taskqueue_queues_lock, LK_EXCLUSIVE);
118 STAILQ_INSERT_TAIL(&taskqueue_queues, queue, tq_link);
119 lockmgr(&taskqueue_queues_lock, LK_RELEASE);
125 taskqueue_terminate(struct thread **pp, struct taskqueue *tq)
127 while(tq->tq_tcount > 0) {
129 TQ_SLEEP(tq, pp, "taskqueue_terminate");
134 taskqueue_free(struct taskqueue *queue)
137 queue->tq_flags &= ~TQ_FLAGS_ACTIVE;
138 taskqueue_run(queue, 1);
139 taskqueue_terminate(queue->tq_threads, queue);
142 lockmgr(&taskqueue_queues_lock, LK_EXCLUSIVE);
143 STAILQ_REMOVE(&taskqueue_queues, queue, taskqueue, tq_link);
144 lockmgr(&taskqueue_queues_lock, LK_RELEASE);
146 TQ_LOCK_UNINIT(queue);
148 kfree(queue, M_TASKQUEUE);
152 taskqueue_find(const char *name)
154 struct taskqueue *queue;
156 lockmgr(&taskqueue_queues_lock, LK_EXCLUSIVE);
157 STAILQ_FOREACH(queue, &taskqueue_queues, tq_link) {
158 if (!strcmp(queue->tq_name, name)) {
159 lockmgr(&taskqueue_queues_lock, LK_RELEASE);
163 lockmgr(&taskqueue_queues_lock, LK_RELEASE);
168 * NOTE! If using the per-cpu taskqueues ``taskqueue_thread[mycpuid]'',
169 * be sure NOT TO SHARE the ``task'' between CPUs. TASKS ARE NOT LOCKED.
170 * So either use a throwaway task which will only be enqueued once, or
171 * use one task per CPU!
174 taskqueue_enqueue(struct taskqueue *queue, struct task *task)
182 * Don't allow new tasks on a queue which is being freed.
184 if ((queue->tq_flags & TQ_FLAGS_ACTIVE) == 0) {
190 * Count multiple enqueues.
192 if (task->ta_pending) {
199 * Optimise the case when all tasks have the same priority.
201 prev = STAILQ_LAST(&queue->tq_queue, task, ta_link);
202 if (!prev || prev->ta_priority >= task->ta_priority) {
203 STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link);
206 for (ins = STAILQ_FIRST(&queue->tq_queue); ins;
207 prev = ins, ins = STAILQ_NEXT(ins, ta_link))
208 if (ins->ta_priority < task->ta_priority)
212 STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link);
214 STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link);
217 task->ta_pending = 1;
218 if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0) {
219 if (queue->tq_enqueue)
220 queue->tq_enqueue(queue->tq_context);
222 queue->tq_flags |= TQ_FLAGS_PENDING;
231 taskqueue_block(struct taskqueue *queue)
234 queue->tq_flags |= TQ_FLAGS_BLOCKED;
239 taskqueue_unblock(struct taskqueue *queue)
242 queue->tq_flags &= ~TQ_FLAGS_BLOCKED;
243 if (queue->tq_flags & TQ_FLAGS_PENDING) {
244 queue->tq_flags &= ~TQ_FLAGS_PENDING;
245 if (queue->tq_enqueue)
246 queue->tq_enqueue(queue->tq_context);
252 taskqueue_run(struct taskqueue *queue, int lock_held)
259 while (STAILQ_FIRST(&queue->tq_queue)) {
261 * Carefully remove the first task from the queue and
262 * zero its pending count.
264 task = STAILQ_FIRST(&queue->tq_queue);
265 STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link);
266 pending = task->ta_pending;
267 task->ta_pending = 0;
268 queue->tq_running = task;
271 task->ta_func(task->ta_context, pending);
274 queue->tq_running = NULL;
282 taskqueue_drain(struct taskqueue *queue, struct task *task)
285 while (task->ta_pending != 0 || task == queue->tq_running)
286 TQ_SLEEP(queue, task, "-");
291 taskqueue_swi_enqueue(void *context)
297 taskqueue_swi_run(void *arg, void *frame)
299 taskqueue_run(taskqueue_swi, 0);
303 taskqueue_swi_mp_run(void *arg, void *frame)
305 taskqueue_run(taskqueue_swi_mp, 0);
309 taskqueue_start_threads(struct taskqueue **tqp, int count, int pri, int ncpu,
310 const char *fmt, ...)
314 struct taskqueue *tq;
316 char ktname[MAXCOMLEN];
325 kvsnprintf(ktname, MAXCOMLEN, fmt, ap);
328 tq->tq_threads = kmalloc(sizeof(struct thread *) * count, M_TASKQUEUE,
331 for (i = 0; i < count; i++) {
333 * If no specific cpu was specified and more than one thread
334 * is to be created, we distribute the threads amongst all
337 if ((ncpu <= -1) && (count > 1))
341 error = lwkt_create(taskqueue_thread_loop, tqp,
342 &tq->tq_threads[i], NULL,
346 error = lwkt_create(taskqueue_thread_loop, tqp,
347 &tq->tq_threads[i], NULL,
352 kprintf("%s: kthread_add(%s): error %d", __func__,
354 tq->tq_threads[i] = NULL;
356 td = tq->tq_threads[i];
357 lwkt_setpri_initial(td, pri);
367 taskqueue_thread_loop(void *arg)
369 struct taskqueue **tqp, *tq;
374 while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) {
375 taskqueue_run(tq, 1);
376 TQ_SLEEP(tq, tq, "tqthr");
379 /* rendezvous with thread that asked us to terminate */
381 wakeup_one(tq->tq_threads);
387 taskqueue_thread_enqueue(void *context)
389 struct taskqueue **tqp, *tq;
397 TASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, 0,
398 register_swi(SWI_TQ, taskqueue_swi_run, NULL, "swi_taskq", NULL));
400 * XXX: possibly use a different SWI_TQ_MP or so.
401 * related: sys/interrupt.h
402 * related: platform/XXX/isa/ipl_funcs.c
404 TASKQUEUE_DEFINE(swi_mp, taskqueue_swi_enqueue, 0,
405 register_swi(SWI_TQ, taskqueue_swi_mp_run, NULL, "swi_mp_taskq", NULL));
407 struct taskqueue *taskqueue_thread[MAXCPU];
414 lockinit(&taskqueue_queues_lock, "tqqueues", 0, 0);
415 STAILQ_INIT(&taskqueue_queues);
417 for (cpu = 0; cpu < ncpus; cpu++) {
418 taskqueue_thread[cpu] = taskqueue_create("thread", M_INTWAIT,
419 taskqueue_thread_enqueue, &taskqueue_thread[cpu]);
420 taskqueue_start_threads(&taskqueue_thread[cpu], 1,
421 TDPRI_KERN_DAEMON, cpu, "taskq_cpu %d", cpu);
425 SYSINIT(taskqueueinit, SI_SUB_PRE_DRIVERS, SI_ORDER_ANY, taskqueue_init, NULL);